Summary: The middle area of the state of Sinaloa in Northwestern Mexico is characterized by a warm semi-arid climate where rainfall is insufficient for the adequate development of some introduced plant species. For example, those that correspond to the genus Brachiaria, despite technological advances in sencor development, the producers have limted access to sufficient meteorological information. Therefore, the aim in the present study is to determine water requirement, crop coefficient, and productivity of Convert 300 hybrid grass (Brachiaria sp) in a warm semiarid climate of Mexico by using the Food and Agriculture Organization (FAO56 Penman-Montiel equation) method with complete and limited data; a meteorological station was used to measure climatic parameters, and the FAO56 method with dual kc was applied to estimate crop evapotranspiration under non-standard conditions, and subsequently, water productiviy. The estimated water consumption for the Convert 330 hybrid in the warm semiarid climate of northwest Mexico was 1849 mm with measured data and 1973.5 mm with limited data. The statistical analyses yielded a coefficient of determination (R2) of 0.92, Willmott’s coefficient of agreement (d) of 0.90, RMSE of 0.694 mm d-1, BIAS of 0.380 mm d-1 and a Nash-Sutcliffe coefficient of efficiency (EF) of 0.98. The kc values were 0.49, 1.11 and 1.04 for initial, middle and end of season, respectively; the water productivity (WUE) was 2.666 kg m-3 for green forage, and 0.726 kg m-3, for dry matter, in the same way, 375.1 and 1378 L kg-1 were required to produce green forage and dry matter, respectively. To conclude, althought the ETc estimation with limited data overestimated the ETc with measured data by 6.7%, statistics showed that the procedure is reliable.

Resumen: La región central del estado de Sinaloa en el noroeste mexicano, se caracteriza por un clima semiárido cálido donde la precipitación es insuficiente para el desarrollo adecuado de algunas especies vegetales introducidas, como las correspondientes al género Brachiaria, a pesar del avance tecnológico en el desarrollo de sensores, es escaso el acceso de los productores a suficiente información meteorológica; el objetivo del presente trabajo consistió en determinar el requerimiento hídrico, coeficiente de cultivo y productividad del pasto híbrido Convert 330 (Brachiaria sp) en un clima semiárido cálido de México, utilizando el método FAO56 con datos medidos y datos limitados; se utilizó una estación meteorológica para medir los parámetros climáticos, y se aplicó el método FAO56 con kc dual para estimar la evapotranspiración de cultivo bajo condiciones no estándar, y posteriormente, la productividad del agua. El consumo de agua estimado para el pasto Convert 330 en clima semiárido cálido del noroeste de México fue de 1849 mm con datos medidos y 1973.5 mm con datos limitados; el análisis estadístico arrojó un coeficiente de determinación (R2) de 0.92, coeficiente de concordancia de Willmott (d) de 0.90, RMSE de 0.694 mm d-1, BIAS=0.380 mm d-1 y un coeficiente de eficiencia de Nash-Sutcliffe (EF) de 0.98. Los valores de kc obtenidos fueron de 0.49, 1.11 y 1.04 paras las etapas inicial, media y final, respectivamente; la productividad del agua (EUA) fue de 2.666 kg m-3 para forraje verde y 0.726 kg m-3 para materia seca; asimismo, se requirieron 375.1 y 1378 L kg-1 para la producción de forraje verde y materia seca, respectivamente. Finalmente, se concluye que, aunque la estimación de la ETc con datos limitados sobrestimó en un 6.7% la ETc con datos medidos, la estadística muestra que es confiable el procedimiento.

Abstract. Mercury (Hg) is mainly incorporated into humans through the consumption of contaminated foods. Mercury was measured and the methyl-Hg (MeHg) concentration was estimated in canned mollusks sold in northwestern Mexico to assess the health risk to consumers. Five mollusk types were considered: oysters, clams, octopuses, mussels, and squids. The Hg concentration of mussels was significantly (P < 0.05) lower than those of the other bivalves (oysters and clams) and cephalopods (squids and octopuses). The average Hg concentration in bivalves (0.013 mg·kg-1) was significantly (P < 0.05) lower than that of cephalopods (0.018 mg·kg-1). The estimated MeHg concentrations were also lower in bivalves than in cephalopods. Based on our results, no health risk is associated with the consumption of canned mollusks that are sold in northwestern Mexico. The Hg and MeHg concentrations followed the order of octopuses > squids = clams > oysters > mussels. The Hg and MeHg concentrations in the mollusks evaluated in this study were below the maximum permissible limits for human consumption in Mexico.

Resumen. El mercurio (Hg) se incorpora principalmente en los seres humanos a través del consumo de alimentos contaminados. Se midió el Hg y se estimó el metilmercurio (MeHg) en moluscos enlatados que se venden en el noroeste de México para evaluar el riesgo para la salud de los consumidores. Se consideraron 5 tipos de moluscos: ostiones, almejas, pulpos, mejillones y calamares. La concentración de Hg en los mejillones fue significativamente (P < 0.05) más baja que la de los otros bivalvos (ostras y almejas) y cefalópodos (calamares y pulpos). La concentración promedio de Hg en los bivalvos (0.013 mg·kg-1) fue significativamente (P < 0.05) menor que la de los cefalópodos (0.018 mg·kg-1). Las concentraciones estimadas de MeHg también fueron menores en los bivalvos que en los cefalópodos. De acuerdo con nuestros resultados, no existe riesgo relacionado con el consumo de moluscos enlatados en el noroeste de México. La secuencia de las concentraciones de Hg fue pulpos > calamares = almejas > ostiones > mejillones. Las concentraciones de Hg y MeHg en los moluscos evaluados en este estudio estaban por debajo de los límites máximos permitidos para el consumo humano en México.

ABSTRACT BACKGROUND: Gallbladder polyps are becoming a common finding in ultrasound. The management has to consider the potential risk of malignant lesions. AIMS: The aim of this study was to analyze the ultrasound findings in patients undergoing cholecystectomy due to gallbladder polyps and compare them for histopathological findings (HPs). METHODS: Patients with an ultrasonographic diagnosis of gallbladder polyp and who underwent cholecystectomy from 2007 to 2020 were included in the study. RESULTS: A total of 447 patients were included, of whom 58% were women. The mean age was 45±12 years. The mean size of polyps in US was 7.9±3.6 mm. Notably, 9% of polyps were greater than 10 mm, and single polyps were significantly larger than the multiple ones (p=0.003). Histopathological findings confirmed the presence of polyps in 88.4%, with a mean size of 4.8±3.4 mm. In all, 16 cases were neoplastic polyps (4.1%), 4 of them being malignancies, and all were single and larger than 10 mm. We found a significant correlation between ultrasound and histopathological findings polyp size determination (r=0.44; p<0.001). The Bland-Altman analysis obtained an overestimation of the US size of 3.26 mm. The receiver operating characteristic (ROC) curve analysis between both measures obtained an area under the receiver operating characteristic curve (AUC) of 0.77 (95%CI 0.74–0.81). Ultrasound polyps size larger than 10 mm had an odds ratio (OR) of 8.147 (95%CI 2.56–23.40) for the presence of adenoma and malignancy, with a likelihood ratio of 2.78. CONCLUSIONS: There is a positive correlation and appropriate diagnostic accuracy between ultrasound size of gallbladder polyps compared to histopathological records, with a trend to overestimate the size by about 3 mm. Neoplastic polyps are uncommon, and it correlates with size. Polyps larger than 10 mm were associated with adenoma and malignancy. BACKGROUND lesions AIMS HPs. HPs . (HPs) METHODS 200 202 RESULTS 44 58 women 4512 45 12 45±1 years 7936 7 9 6 7.9±3. Notably 1 p=0.003. p0003 p p=0.003 0 003 (p=0.003) 884 88 88.4% 4834 8 4.8±3. 4.1%, 41 4.1% , (4.1%) malignancies r=0.44 r044 r (r=0.44 p<0.001. p0001 p<0.001 001 p<0.001) BlandAltman Bland Altman 326 26 3.2 ROC (ROC AUC (AUC 077 77 0.7 95%CI 95CI CI 95 0.74–0.81. 074081 0.74–0.81 74 81 0.74–0.81) OR (OR 8147 147 8.14 2.56–23.40 2562340 2 56 23 40 malignancy 278 78 2.78 CONCLUSIONS records uncommon (HPs 20 5 451 45± 793 7.9±3 p000 p=0.00 00 (p=0.003 88.4 483 4.8±3 4.1 (4.1% r=0.4 r04 (r=0.4 p<0.00 32 3. 07 0. 07408 0.74–0.8 814 14 8.1 2.56–23.4 256234 27 2.7 79 7.9± p00 p=0.0 (p=0.00 88. 48 4.8± 4. (4.1 r=0. r0 (r=0. p<0.0 0740 0.74–0. 8. 2.56–23. 25623 2. 7.9 p0 p=0. (p=0.0 4.8 (4. r=0 (r=0 p<0. 074 0.74–0 2.56–23 2562 7. p=0 (p=0. (4 r= (r= p<0 0.74– 2.56–2 256 p= (p=0 ( (r p< 0.74 2.56– 25 (p= 2.56 (p 2.5

RESUMO RACIONAL: Os pólipos da vesícula biliar estão se tornando um achado comum na ultrassonografia (US). O manejo deve levar em consideração o risco de lesões malignas. OBJETIVOS: Analisar os achados da ultrassonografia em pacientes submetidos à colecistectomia por pólipos vesicais e compará-los com os achados histopatológicos. MÉTODOS: Foram revisados os prontuários médicos dos pacientes com diagnóstico ultrassonográfico de pólipo vesicular e submetidos à colecistectomia no período de 2007 a 2020. RESULTADOS: Foram incluídos no estudo 447 pacientes. A média de idade foi 45±12anos, sendo 58% mulheres. O tamanho médio dos pólipos na US foide 7,9±3,6mm. Nove por cento foram maiores que 10 mm, e os pólipos únicos encontrados foram maiores do que os múltiplos (p=0,003). A HP confirmou a presença de pólipos em 88,4%, tamanho médio 4,8±3,4mm. Dezesseis eram pólipos neoplásicos (4,1%) e quatro deles malignos, únicos e maiores que 10 mm. Foi encontrado correlação significativa entre a determinação do tamanho do pólipo ao ultrassonografia e histopatológicos (r=0,44; p<0,001). A análise de Bland-Altman obteve uma superestimação do tamanho do pólipo ao US em 3,26 mm. A análise da curva da característica de operação do receptor entre as duas medidas obteve uma área sob a curva curva da característica de operação do receptor (AUC) de 0,77 (IC95% 0,74–0,81). Pólipos ao ultrassonografia maiores que 10 mm apresentaram razão de chance (OR) de 8,147 (IC95% 2,56–23,40) para presença de adenoma e malignidade, com razão de verossimilhança de 2,78. CONCLUSÕES: Há uma correlação positiva e acurácia diagnóstica apropriada entre o tamanho dos pólipos da vesícula biliar por ultrassonografia em comparação com os achados histopatológicos, com uma tendência de superestimar o tamanho em cerca de 3 mm. Pólipos maiores que 10 mm foram associados a adenoma e malignidade. RACIONAL US. . (US) malignas OBJETIVOS comparálos compará los MÉTODOS 200 2020 RESULTADOS 44 4512anos anos 45 12anos 45±12anos 58 mulheres 7936mm 7 9 6mm 7,9±3,6mm 1 p=0,003. p0003 p p=0,003 0 003 (p=0,003) 884 88 4 88,4% 4834mm 8 4mm 4,8±3,4mm 4,1% 41 (4,1% malignos r=0,44 r044 r (r=0,44 p<0,001. p0001 p<0,001 001 p<0,001) BlandAltman Bland Altman 326 26 3,2 AUC (AUC 077 77 0,7 IC95% IC95 IC (IC95 0,74–0,81. 074081 0,74–0,81 74 81 0,74–0,81) OR (OR 8147 147 8,14 2,56–23,40 2562340 2 56 23 40 malignidade 278 78 2,78 CONCLUSÕES (US 20 202 5 p000 p=0,00 00 (p=0,003 88,4 4,1 (4,1 r=0,4 r04 (r=0,4 p<0,00 32 3, 07 0, IC9 (IC9 07408 0,74–0,8 814 14 8,1 2,56–23,4 256234 27 2,7 p00 p=0,0 (p=0,00 88, 4, (4, r=0, r0 (r=0, p<0,0 (IC 0740 0,74–0, 8, 2,56–23, 25623 2, p0 p=0, (p=0,0 (4 r=0 (r=0 p<0, 074 0,74–0 2,56–23 2562 p=0 (p=0, ( r= (r= p<0 0,74– 2,56–2 256 p= (p=0 (r p< 0,74 2,56– 25 (p= 2,56 (p 2,5

Laparoscopic cholecystectomy (LC) is the standard of treatment for benign pathologies such as cholelithiasis and gallbladder polyps. The LC is one of the most frequent procedures in general surgery, with a 0.1%-0.3% associated risk of bile duct injury. Currently, scientific society programs, surgical strategies, and new technologies allow us to reduce the risk of bile duct injuries and to increase the clinical safety of this procedure. This document aims to review the strategies, technologies, and tactics to carry out a safe LC beyond the critical vision of security.

Resumen La colecistectomía laparoscópica (CL) es el estándar de tratamiento para la patología benigna como la colelitiasis y los pólipos de la vesícula biliar y es uno de los procedimientos más frecuentes de la cirugía general. Esta intervención tiene un riesgo de 0,1%-0,3% de causar una lesión quirúrgica de la vía biliar (LQVB). En la actualidad, existen programas de sociedades científicas, estrategias de abordaje y tecnologías que nos permiten reducir las LQVB mejorando la seguridad clínica de este procedimiento. El objetivo de este documento es realizar una revisión de las estrategias, tecnologías y maniobras para realizar una CL segura más allá de la visión crítica de seguridad.

Introduction: Although intracorporeal anastomosis has demonstrated clinical benefits over extracorporeal anastomosis in laparoscopic right hemicolectomy, its application has been limited due to its technical difficulty and longer learning curve. The present study aims to develop and evaluate a simulated model to train this procedure. Materials and Method: An ex vivo tissue model was developed with porcine colon and bovine small bowel mounted in a laparoscopic simulator. This was subsequently modified based on semi-structured interviews to experts until the final model was achieved. To evaluate appearance and reaction to the model, the participants performed an ileocolic mechanical anastomosis in the model and answered a survey. Results: Twelve subjects participated. Four colorectal surgeons, 4 colorectal surgery fellows, 2 residents of general surgery, 1 general surgeon and 1 upper digestive surgeon. Of all subjects, 91.6%, 83.3% and 75% deemed ergonomics achieved, the use of instruments, and the anatomical relationship between structures as similar to reality, respectively. All participants deemed the model useful to train laparoscopic manual suturing, while 91.6% and 83.3% of them considered it useful to train enterotomies and the use of an endostapler, respectively. All declared that the model allows to understand the proposed technique. Conclusion: This model would be useful to train critical skills to perform an intracorporeal anastomosis in laparoscopic right hemicolectomy. Its incorporation into an advanced simulated laparoscopy training program could help shorten the learning curve of this procedure.

Resumen Introducción: Si bien la anastomosis intracorpórea (AI) ha demostrado beneficios clínicos sobre la anastomosis extracorpórea (AE) en la hemicolectomía derecha laparoscópica (HDL), su aplicación ha sido limitada por su dificultad técnica y curva de aprendizaje más larga. El presente estudio busca desarrollar y evaluar un modelo simulado para entrenar este procedimiento. Materiales y Método: Se desarrolló un modelo en base a tejido ex vivo, con colon porcino e intestino bovino, montados en un simulador de laparoscopía. Este se modificó sucesivamente en base a entrevistas semiestructuradas a cirujanos hasta lograr el modelo final. Para evaluar apariencia y reacción al modelo, coloproctólogos, cirujanos y residentes previamente expuestos a entrenamiento simulado, realizaron una ileotransverso anastomosis mecánica en el modelo y luego contestaron una encuesta. Resultados: Doce sujetos participaron. Cuatro coloproctólogos, 4 residentes de coloproctología, 2 residentes de cirugía general, 1 cirujano general y 1 cirujano digestivo. El 91,6% valoró positivamente la ergonomía lograda, mientras que el 83,3% y 75% valoraron positivamente el uso del instrumental y la relación anatómica entre estructuras, respectivamente. Todos los participantes consideraron el modelo útil para entrenar sutura manual laparoscópica, el 91,6% para entrenar enterotomías y 83,3% para entrenar el uso de endograpadora. Todos declararon que el módulo permite entender y reflexionar sobre la técnica propuesta. Conclusión: Este modelo desarrollado sería útil para entrenar habilidades críticas para realizar una AI en HDL. Su incorporación a un programa de entrenamiento en laparoscopía avanzada podría contribuir a acortar la curva de aprendizaje de este procedimiento.

RESUMO Racional: Os procedimentos pediátricos têm dificuldade de serem realizados em espaços reduzidos. O treinamento nesses espaços provou ser diferente em dificuldade em comparação aos endotrainers laparoscópicos adultos. Objetivo: Desenvolver e validar um novo endotrainer neonatal com espaço reduzido. Métodos: O simulador foi criado, testado e avaliado por usuários com diferentes níveis de habilidade e experiência em cirurgia pediátrica laparoscópica por meio de um questionário de oito itens. A validação do método foi determinada pela avaliação do desempenho de cada participante em nove exercícios. Resultados: Foi criado um simulador acrílico de 10,5 x 10 x 18 cm, com uma superfície de trabalho interna de 9 x 9 cm. Uma câmera HD foi incorporada com faixa de movimento de 0-180°. Todos os exercícios do Programa de Treinamento Laparoscópico Básico foram adaptados em escala de 1:0,5 para se ajustarem. Dos 49 participantes, 42 (85,71%) responderam à pesquisa; 80,5% consideraram que o simulador reproduz condições semelhantes às de procedimentos realizados em crianças menores de um ano; 61,1% consideraram que o simulador representa dificuldade semelhante aos procedimentos realizados em recém-nascidos; 73,7% consideraram que o simulador neonatal é mais difícil que o simulador adulto. Especialistas apresentaram desempenho significativamente melhor em todos os exercícios propostos. Conclusão: O simulador possui imagem de alta qualidade e design que permitem o treinamento com exercícios básicos. O aparelho permitiu discriminar entre os diferentes níveis de habilidade e foi bem avaliado por usuários com experiência cirúrgica diversificada.

ABSTRACT Background: Pediatric procedures have the difficulty of being performed in reduced spaces. Training in reduced spaces has proven to be different in complexity compared to adult laparoscopic endotrainers. Aim: To develop and validate a new neonatal/reduced-space endotrainer. Methods: The simulator was tested and assessed by users with different skill levels and experience in laparoscopic pediatric surgery through an 8-item questionnaire. Construct validity was determined by evaluating the performance of each subject on nine exercises. Results: A 10.5 x 10 x 18 cm acrylic simulator was created, with an internal working surface of 9 x 9 cm. An HD camera was incorporated, with a 0-180° range of movement. All exercises of a Basic Laparoscopic Training Program were adapted on a scale of 1:0.5 to fit in. From 49 participants, 42 (85.71%) answered the survey; 80.5% considered that the simulator reproduces similar conditions to procedures performed in children under one year of age; 61.1% thought that the simulator represents a difficulty identical to procedures performed in newborns; 73.7% considered that the neonatal simulator is more complicated than the adult simulator. Experts showed significantly better performance in all proposed exercises. Conclusion: The simulator has a high-quality image and design that allows training with basic tasks. The endotrainer permitted to discriminate between these different skill levels and was well evaluated by users with diverse surgical experience.

Background: Standardized Simulated Training (SST) has shown to improve both resident and surgeon skills. However, Simulation Centers with validated training programs are scarce and centralized. The current challenge is to provide the surgical community access to these programs. Aim: To describe the first Learning Center (LC), launched during the 90th Chilean Surgical Congress, and to assess its impact and attendees’ perception on simulation in Minimally Invasive Surgery (MIS) in current surgery residency programs. Materials and Method: Cross-sectional study. LC characteristics are described. A Likert survey was applied to assess its impact and attendees’ perception. Inclusion criteria: to have performed ≥ 1 training sessions. Exclusion criteria: incomplete surveys. Descriptive and non-parametric analytical statistics were applied. Results: The LC was composed of 10 training stations with different difficulty levels. Nine instructors monitored and gave attendees effective feedback. 84 attendees answered the survey adequately. 39% were women. The sample was composed of 41.6% General Surgery Residents, 35.7% Surgeons, 17.9% Medicine Clerks and 4.8% General Practitioners. 85% of participants agreed regarding both the positive impact of the LC as a continuous educational resource during the congress and SST usefulness in development of MIS skills. There were no significant differences according to sex or medical degree. Conclusion: The first LC was widely accepted amongst its participants, constituting a possible permanent resource in the Chilean Surgical Congress. SST in MIS seems to be an accepted resource and perceived as a necessity by the national surgical community.

Resumen Introducción: El entrenamiento estandarizado mediante simulación ha demostrado mejorar habilidades de residentes y cirujanos. Sin embargo, los centros de simulación que imparten programas validados son escasos y centralizados. Favorecer el acceso de la comunidad quirúrgica a estos programas constituye el desafío actual. Objetivo: Describir el primer “Learning Center” (LC) realizado durante el 90° Congreso Chileno de Cirugía, evaluar su impacto y percepción de los asistentes sobre simulación en cirugía mínimamente invasiva (CMI) en los programas de formación actual. Materiales y Método: Estudio de corte transversal. Se describieron las características del LC. Se aplicó una encuesta tipo Likert para evaluar impacto y percepción de los asistentes. Criterios de inclusión: completar ≥ 1 sesión de entrenamiento, exclusión: encuesta incompleta. Se aplicó estadística descriptiva y analítica no paramétrica. Resultados: LC se compuso de 10 estaciones de entrenamiento con distintos niveles de dificultad. Un equipo de 9 instructores monitorizaron y entregaron feedback efectivo a los asistentes. 84 asistentes contestaron la encuesta completa, 39% mujeres. La muestra se conformó por 41,6% residentes de cirugía general, 35,7% cirujanos, 17,9% internos de medicina, y 4,8% médicos generales. 85% manifestó acuerdo con el impacto positivo del LC como recurso educacional continuo durante el congreso, y la utilidad de la práctica simulada para el desarrollo de habilidades en CMI. No hubo diferencias significativas según sexo o nivel de formación. Conclusión: El primer LC se desarrolló con una amplia aceptación entre sus participantes, constituyendo un posible recurso permanente. El entrenamiento simulado en CMI parece ser un recurso aceptado y percibido como una necesidad por la comunidad quirúrgica nacional.

RESUMO Racional: Residência em Cirurgia Geral pode durar entre 2-6 anos, dependendo do país. Residência mais curta deve otimizar a exposição dos residentes às cirurgias. Sabe-se que o treinamento cirúrgico simulado encurta as curvas de aprendizado, mas a informação relacionada à como isso afeta a residência em relação à exposição clínica é escassa. Objetivo: Analisar o efeito da introdução de um programa de treinamento laparoscópico simulado validado em procedimentos abdominais realizados por residentes em um programa de Residência em Cirurgia Geral de três anos. Métodos: Um estudo de coorte não simultâneo foi desenhado. Quatro gerações (2012-2015) de cirurgiões graduados foram incluídos. Apenas os procedimentos abdominais em que os cirurgiões graduados foram o cirurgião principal foram descritos e analisados. O grupo controle foi de cirurgiões graduados de 2012 sem programa de treinamento laparoscópico simulado. Procedimentos cirúrgicos por ano de programa, técnica cirúrgica, intervenção de emergência ou eletiva e local do hospital (hospitais principais/comunitários) foram descritos. Resultados: Intervenções de 28 cirurgiões graduados foram analisadas (controle=5; programa de treinamento simulado=23). Os cirurgiões graduados realizaram média de 372 procedimentos abdominais, com maior número médio de procedimentos de médio a complexo no grupo de programa de treinamento simulado (48 vs. 30, p=0,02). Cirurgiões graduados treinados com programa de treinamento simulado realizaram número maior de procedimentos abdominais totais (384 vs. 319, p=0,04) e procedimentos laparoscópicos (183 vs. 148, p<0,05). Conclusões: A introdução do programa de treinamento laparoscópico simulado pode aumentar o número e a complexidade dos procedimentos totais e laparoscópicos na Residência em Cirurgia Geral de três anos.

ABSTRACT Background: A General Surgery Residency may last between 2-6 years, depending on the country. A shorter General Surgery Residency must optimize residents’ surgical exposure. Simulated surgical training is known to shorten the learning curves, but information related to how it affects a General Surgery Residency regarding clinical exposure is scarce. Aim: To analyze the effect of introducing a validated laparoscopic simulated training program in abdominal procedures performed by residents in a three-year General Surgery Residency program. Methods: A non-concurrent cohort study was designed. Four-generations (2012-2015) of graduated surgeons were included. Only abdominal procedures in which the graduated surgeons were the primary surgeon were described and analyzed. The control group was of graduated surgeons from 2012 without the laparoscopic simulated training program. Surgical procedures per program year, surgical technique, emergency/elective intervention and hospital-site (main/community hospitals) were described. Results: Interventions of 28 graduated surgeons were analyzed (control group=5; laparoscopic simulated training program=23). Graduated surgeons performed a mean of 372 abdominal procedures, with a higher mean number of medium-to-complex procedures in laparoscopic simulated training program group (48 vs. 30, p=0.02). Graduated surgeons trained with laparoscopic simulated training program performed a higher number of total abdominal procedures (384 vs. 319, p=0.04) and laparoscopic procedures (183 vs. 148, p<0.05). Conclusions: The introduction of laparoscopic simulated training program may increase the number and complexity of total and laparoscopic procedures in a three-year General Surgery Residency.

Antidepressant use in the perioperative is a common practice, and clinical evidence shows that surgical patients using antidepressants have an increased perioperative risk. There are not evidence-based guidelines for the perioperative management of these patients, and recommendations are based on few systematic reviews and meta-analysis, case reports and expert opinion, which in many cases are controversial. The decision to continue or discontinue the medication involves considering general patient characteristics, risks associated with the antidepressant used, type of surgery, interaction with drugs commonly used in the perioperative, risk of withdrawal symptoms, relapse of psychiatric disease and suicide risk, so decision should be made between surgeons, anesthesiologists and psychiatrists, in order to design a safe management plan for the patient who undergo surgery.

El uso de antidepresivos en el perioperatorio es muy frecuente, y la práctica clínica indica que los pacientes usuarios de antidepresivos que son sometidos a cirugía tienen un riesgo perioperatorio aumentado. No existen en la actualidad guías clínicas basadas en la evidencia que orienten el manejo de este tipo de pacientes, por lo que las recomendaciones se basan en las escasas revisiones sistemáticas y metaanálisis disponibles, reportes de casos y opinión de expertos, que en muchos casos resultan controversiales. La decisión de mantener o suspender la medicación antidepresiva implica considerar los riesgos tanto desde el punto de vista fisiológico (características generales del paciente, riesgos asociados al antidepresivo utilizado, la cirugía propiamente como tal, la interacción con fármacos frecuentemente utilizados en el perioperatorio, entre otros) como desde el punto de vista psiquiátrico (riesgo de síndrome de retirada, recaída de la enfermedad psiquiátrica, intentos suicidas), por lo que la decisión debe ser tomada idealmente de forma multidisciplinaria entre cirujanos, anestesiólogos y psiquiatras, con la idea de confeccionar un plan quirúrgico, anestésico y de manejo perioperatorio seguro para el paciente.

Congenital absence of the hepatic portal vein is an extremely rare malformation that was first described by John Abernethy in 1793. Only 101 cases had been described in the literature until 2015 and most affected females. In this anomaly, also known as congenital extrahepatic porto-systemic shunt (CEPS), intestinal venous drainage is derived towards the territory of the systemic veins and could be associated with other birth defects, including heart and biliary tract anomalies, metabolic diseases, mental retardation. We present the case of a 2-year-old boy who died because of multifocal pneumonia and necropsy showed anatomical findings consistent with this malformation as an incidental finding. The portal vein followed an anomalous course and joined the right renal vein, forming the "mesenteric-splenic-renal" venous collector, which then received the right gonadal vein and ended at the confluence of the common iliac veins. In our case this anomaly was associated to intestinal malrotation, aberrant hepatic artery and persistent left inferior vena cava, situation described once in the literature. The finding of these anatomical abnormalities in cadavers has a great teaching value for our undergraduate and graduate students who are learning anatomy and they can also assess the associated clinical.

La ausencia congénita de la vena porta hepática es una malformación en extremo rara, fue descrita por primera vez en 1793 por John Abernethy y a la fecha se han reportado sólo 101 casos. Afecta con mayor frecuencia a mujeres y determina que el drenaje venoso intestinal sea derivado hacia el territorio de las venas sistémicas. Es también conocida como derivación porto-sistémica extra hepática congénita (CEPS), por su sigla en inglés, y se asocia a otras alteraciones congénitas,incluyendo anomalías cardíacas, de las vías biliares, enfermedades metabólicas y retardo mental. En este trabajo presentamos el hallazgo de esta malformación en el cadáver de un niño de dos años de edad, donde la vena porta seguía un trayecto anómalo y se unía a la vena renal derecha. El confluente venoso "mesentérico-esplénico-renal" así formado presentaba un trayecto descendente, recibía a la vena gonadal derecha, y desembocando en la confluencia de las venas ilíacas comunes. Esto se asociaba a mal rotación intestinal, arteria hepática aberrante y a vena cava inferior izquierda, situación descrita sólo una vez en la literatura. El hallazgo de estas anomalías anatómicas en los cadáveres disecados con fines docentes en nuestro Departamento de Anatomía, tiene un valor formativo indiscutible para nuestros alumnos de pre y postgrado, quienes pueden valorar las implicancias de este conocimiento anatómico en la clínica diaria.

We determined the Hg content of blood, placenta and umbilical cord of 20 pregnant females of the viviparous Pacific sharpnose shark, Rhizoprionodon longurio and of the livers of the embryos contained in their right and left uterus, aiming to provide information on the amount of this metal offloaded during pregnancy by the mother to the embryos. Hg content varied by close or higher than one order of magnitude in all tissues and showed the decreasing trend: maternal blood > umbilical cord > placenta > embryonic livers, with placenta and embryonic livers significantly lower than maternal blood. There were highly significant correlations (P < 0.001) between the Hg content of maternal blood, cord, and placenta. Those between embryonic livers and maternal blood, cord and placenta were not significant (P > 0.05). The results suggest transplacental Hg transfer and that the liver is not the main site of Hg accumulation.

En el presente estudio se determinó el contenido de mercurio en la sangre, placenta y cordón umbilical de 20 hembras del tiburón bironche Rhizoprionodon longurio así como en el hígado de los embriones de los úteros derecho e izquierdo, con el objetivo de proveer información sobre la cantidad de este metal transferida por la madre a sus embriones durante su desarrollo. Los contenidos de Hg variaron hasta un orden de magnitud en todos los tejidos y presentaron el siguiente orden decreciente: sangre materna > cordón umbilical > placenta > hígado de los embriones. Los contenidos de la placenta y el hígado de los embriones fueron significativamente menores al determinado en la sangre materna. Se encontraron correlaciones altamente significativas (P < 0,001) entre el contenido de Hg de la sangre materna, cordón y placenta, mientras que las calculadas entre hígado de los embriones y la sangre materna, cordón y placenta no fueron significativas (P > 0,05). Los resultados sugieren que existe una libre transferencia de Hg y que el hígado no es el sitio principal de acumulación de Hg.

The distribution of sensory nerve branches in the lateral and the back of the hand have been described more accurately in recent decades due to advances in new diagnostic techniques, which have identified that about 40% of the population examined have some degree of anatomical variation in the distribution area of the sensitive nerves involved. The knowledge of the number of fibers forming a sensitive nerve of the hand has become more important with the development of microsurgical techniques and ultrasonography; procedures that have demonstrated the usefulness of this information in the diagnosis and treatment of nerve injuries. Thus, the fascicular architecture, adipose tissue area and the vascular area of a nerve branch, data that has been demonstrated that change with age, will determine the therapeutic and prognosis of nerve injuries. In this case we present an extremely rare and bilateral anatomical variation, involving the superficial branch of radial nerve and the lateral antebrachial cutaneous nerve, a situation that is described in the literature only once and which notably alter the sensory innervations of the radial edge of the hand.

La distribución de los ramos nerviosos sensitivos en el borde lateral y en el dorso de la mano han sido descritos con mayor exactitud en las últimas décadas, debido al avance de nuevas técnicas de diagnóstico, las cuales han permitido detectar que alrededor del 40% de la población examinada presenta algún grado de variación anatómica en el territorio de distribución de los nervios involucrados. Conocer el número de fibras que componen un ramo nervioso cutáneo de la región de la mano, ha adquirido mayor relevancia con el desarrollo de técnicas de microcirugía y de ultrasonografía, procedimientos que han demostrado la utilidad de este conocimiento en el diagnóstico y tratamiento de las lesiones nerviosas. Así, la arquitectura fascicular, el área adiposa y el área vascular de un ramo nervioso determinado constituyen datos que se ha demostrado se modifican con la edad y, en consecuencia, van condicionar la conducta terapéutica y el pronóstico de las lesiones nerviosas. En este caso presentamos una variación anatómica bilateral extremadamente rara, que involucra al ramo superficial del nervio radial y al nervio cutáneo lateral antebraquial; situación que aparece descrita en la literatura especializada sólo una vez y que modifica notablemente la inervación sensitiva del borde radial de la mano.

The distribution of the sensory nerve branches in the lateral and the back of the hand have been described more accurately in the past decades due to advancement of high performance electro-diagnostic variation techniques, which indicate that approximately 40% of the population examined have some degree of anatomical variation in the distribution area of the nerves involved. In this case we present an extremely rare, bilaterally detected variation, involving the superficial branch of the radial nerve (SBRN) and lateral antebrachial cutaneous nerve of the forearm (LABCN), where the SBRN is connected integrally with the medial branch of LABCN, forming a common trunk (CT) distributed by the dorsal region of the hand. Furthermore, the lateral branch of the LABCN is distributed in the lateral border of the hand, occupying the area of the skin of the SBRN, an event that is described only once in the literature. The discovery of these anatomical variations in dissected cadavers for teaching purposes, in the Department of Anatomy, have an undeniable educational value for our undergraduate students and especially for the graduate who can observe the enormous variability of human beings first hand, and value implications of this anatomical knowledge in daily clinic.

La distribución de los ramos nerviosos sensitivos en el borde lateral y en el dorso de la mano han sido descritos con mayor exactitud en las últimas décadas, debido al avance de las técnicas de electrodiagnóstico que ofrecen un alto rendimiento, las cuales han permitido detectar que alrededor del 40% de la población examinada presenta algún grado de variación anatómica en el territorio de distribución de los nervios involucrados. En este caso presentamos una variación anatómica bilateral extremadamente rara, que involucra al ramo superficial del nervio radial (NRS) y al nervio cutáneo antebraquial lateral (CABL); donde NRS se conecta de forma íntegra con el ramo medial de CABL, formándose así un tronco común (TC) que se distribuye por la región dorsal de la mano. Por su parte, el ramo lateral de CABL se distribuye por el borde lateral de la mano, ocupando el territorio cutáneo de NRS; situación que aparece descrita en la literatura especializada sólo una vez. El hallazgo de estas variaciones anatómicas en los cadáveres disecados con fines docentes en nuestro Departamento de Anatomía, tienen un valor formativo indiscutible para nuestros alumnos de pregrado y especialmente para los de postgrado, quienes pueden comprobar de primera mano la enorme variabilidad del ser humano, valorando las implicancias en la clínica diaria de este conocimiento anatómico.

This paper describes the aberrant trajectory of the left renal vein. The present study describes the aberrant trajectory of the left renal vein detected in a cadaver used for teaching purposes in the Department of Anatomy, School of Medicine, Pontificia Universidad Católica de Chile. In this case, the left renal vein has a recurrent, retro aortic downward path, between vertebrae levels L II to L V. At level of L V, the vein curves medially, passing dorsal to the abdominal aorta and joins the left common iliac vein. The recurrent left renal vein has a final diameter of 14.86 mm and receives as tributaries to the adrenal vein, the testicular vein and fine parietal branches of the left lumbar region. The normal right renal vein has diameter of 12.10 mm and converges in the inferior vena cava at 101.85 mm above the point of union of both common iliac veins. At this point, the right common iliac vein has an 18.44 mm caliber while its left counterpart which receives the recurrent left renal vein, has a diameter of 23.74 mm. The cause of this rare anomaly which incidence is around 0.16% and is only scarcely described in the literature, is based in the persistence of the postrenal segment of the left supracardinal vein and closure of the supracardinal and subcardinal anastomosis. This finding, particularly attractive for students during dissection, as they represent a clinical problem since over 40% of these aberrant veins are of interest during surgical procedures of the abdominal aorta.

Este trabajo describe el trayecto aberrante de la vena renal izquierda detectado en un cadáver de sexo masculino, utilizado con fines docentes en nuestro Departamento de Anatomía, cuya causa de muerte fue un cuadro de neumonía intrahospitalaria. En este caso, la vena renal izquierda tiene un trayecto descendente de 89 mm, dispuesta a la izquierda de la aorta abdominal, entre los niveles vertebrales L II-L V. A la altura de la V vértebra lumbar la vena recurrente se curva hacia medial, pasando por dorsal de la aorta abdominal, para abocarse a la vena ilíaca común izquierda justo en el punto donde esta forma, junto con la vena homónima de la antímera derecha, la vena cava inferior. La vena renal izquierda recurrente tiene un calibre final de 14,86 mm y recibe como afluentes a la vena adrenal, la vena gonadal y finas ramas parietales de la región lumbar izquierda. La vena renal derecha, de situación normal, tiene un diámetro de 12,10 mm y desemboca en la vena cava inferior a 101,85 mm del punto de formación de esta. En relación con las tributarias de la vena cava inferior, la vena ilíaca común derecha presenta un calibre de 18,44 mm mientras que su homóloga izquierda, que recibe como afluente a la vena renal recurrente, presenta un diámetro de 23,74 mm. La causa de esta rara anomalía, cuya incidencia es del orden del 0,16% y que aparece escasamente descrita en la literatura, radica en la persistencia del segmento posrrenal de la vena supracardinal izquierda y el cierre de las anastomosis supracardinal y subcardinal. Este hallazgo, que es especialmente atractivo para los alumnos durante la disección, representa un problema en la clínica debido a que más del 40% de estas venas de trayecto aberrante son interesadas en la cirugía de la aorta abdominal.

Juveniles of the white shrimp Litopenaeus vannamei were exposed during 25 days to the Cu2+ concentration commonly used in Mexican shrimp farms, at salinities of 1, 5, and 10 psu, in order to observe possible histological alterations to the antennal glands, midgut, gills and hepatopancreas. Survival was 100% in controls and treatments, and no histopathologies were observed in gills, midgut and antennal glands. Sloughing of epithelial cells (< 75%), infiltration of hemocytes (< 75%) and reduction in R and B cells (100%) were observed after 10 days in the hepatopancreas of shrimps exposed to Cu2+ at the lowest salinity and, to a lower degree, at salinities of 5 and 10 psu. This should be taken into consideration to establish criteria of acceptable water quality for inland aquaculture, because the interaction metal-salinity may induce adverse shrimp responses.

Juveniles del camarón blanco Litopenaeus vannamei fueron expuestos durante 25 días a salinidades de 1, 5, y 10 ups y a la concentración de Cu2+ que se usa comúnmente en las granjas camaronícolas de México, con el propósito de observar posibles alteraciones histológicas en la glándula antenal, intestino medio, branquias y hepatopáncreas. La supervivencia fue de 100% en controles y tratamientos y no se observaron histopatologías en branquias, intestino y glándula antenal. Después de 10 días de exposición al Cu2+ a la salinidad más baja, se observaron en el hepatopáncreas desprendimiento de las células epiteliales (< 75%), infiltración de hemocitos (< 75%), y una reducción de las células R y B (100%). Las mismas alteraciones se presentaron, aunque en menor grado, a las salinidades de 5 y 10 ups. Estos efectos deberían ser considerados para establecer criterios de calidad de agua para el cultivo de camarón en agua continentales, debido a que la interacción metal-salinidad puede inducir respuestas adversas en los camarones.